Refractory material.



UNITED sTArnsrg'rENT orrncn.

wanna manna,

0F SCHENECTADY, NEW YORK, ASSIGNOE TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

REFRACTORY MATERIAL.

1,072,414. He Drawing.

;fractory, inert material of low heat conductivity is required.

In accordance with my invention, a charge of silica, carbon and rutile is submitted to a temperature at which reduction takes place with the formation, of vaporous products which condensein the form of a flabby, fu'ngoid-like masses, containing silicon, carbon, oxygen, titanium, and other metallic elements. My invention includes this new product which has a very low heatconductivity and low temperature coeflicient.

In carrying the invention into effect, a mixture by weight of about 15 parts of silica, 20 parts of commercial rutile and 12 parts of carbon, such as crushed coke, are heated in an electric furnace, conveniently in a socalled, smotheredarc furnace with firebrick walls, the mixturebeing placed be tween and around two opposing carbon electrodes, carrying the current, and out of contact with ach other. In order to condense the resulting sublimed product, a housing is preferably placed around the furnace,

which housing acts as a condensing chamber.

A soft, flaky, laminated material is condensed which has a considerable amount of mechanical coherence, so that it may be picked up as flabby sheets, or irregular masses. It is grayish or yellowish in color, has an apparent density of .06 to .16, a real density of about 2.56 and will withstand a temperature of about 900 to 1100 C. and in some cases even a higher temperature without deterioration or fusion. Its specific thermal resistance is from 900-1200 thermal ohms per inch cube and its temperature re sistance coefficient is very small. Chemically thematerial appears to contain silicon, carbon," oxygen, and titanium besides various impurities. A typical sample conta lns the following elements, but the com osltion 1s slightly variable: 45.51 Si, 7.57 40.13 0, 1.07 Ti, .32 Mn, 1.63 A1,, 1.08 Fe. Under Specification of Letters Patent.

Patented Sept. 9, 1 913.

Application filed September 6, 1912. Serial No. 718,825.

the microscope it ordinarily may be observed that the material consists of fine par ticles interlaced with minute acicular, or fiber-like crystals, which apparently gives it its felty structure.

It will be observed that only a small percentage of titanium appears in the product. Other mineral impurities, such as manganese and aluminum, are apparently introduced with the rutile and coke andalso are derived from the fire-brick furnace walls. It is possible that the rutile serves only to modify the physical condition of the charge,

'so as to affect the current distribution and thus the temperature.

Not only is this material of especial value because of its low heat conductivity and refractoriness but I find that it may be compressed to a considerable degree without increasing its heat conductivity materially. This property enables it to be packed firmly in heating or refrigerating devices without substantial loss of heat insulating value.

What I claim as new and desire to secure by Letters Patent of the United States, is,-

1. The process which consists in subjecting a mixture of silica, carbon and a rcfrac tory metallic compound to thereduction temperature in an electric furnace, and condensing the resulting vapor in an inert environment.

2. The process which consists in heating a mixture of silica, carbon and titania in an clect-ric' rc, and condensing the resulting vapors 1n an inert environment.

3. The process which consists in heating 15 parts silica, 12 parts carbon and 20 parts titanium oxid tothe temperature of the electric arc and condensing the resulting vapors in an inert environment.

4:. A flabby, coherent refractory material containing silicon, carbon and oxygen, consisting very largely of a soft powder and containing interlacing fiber-like crystals.

5. A refractory soft, flabby sublimation product, grayish in color, and containing silicon, carbon, oxygen and titanium.

6. A refractory sublimation product having an apparent density of about .O6 to .16, a real density -of about 2.56, a flaky laminated structure and containing silicon, carbon, oxygen and titanium.

7. A refractory sublimation product having an apparent density of about .06 to .16, a real density of about 2.56, grayish in Q Iowan-a color, consisting of fine particlescohering- In witness whereof, I have hereunto set into relatively large masses of fungoid-like my'hand this 4th day of September, 1912. texture, and containing silicon, carbon, oxy- WALTER ARTHUR gen and titanium. v a v 1 5 8. A fungoid-like refractory material of v Witnesses;

low density and low heat conductivity con- BENJAMIN B. HULL, taining silicon, carbon, oxygenand titanium. HE EN 03mm. 

